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SpinLaunch is building a centrifuge to launch satellites into orbit

wired.com

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Re: SpinLaunch is building a centrifuge to launch satellites into orbit

#101

Post by mrfusion »

mlindner wrote: post #68
spicybright wrote: post #5

Earlier quoted context omitted.

Oh wow, I was wondering why bother building housing around it. That seems incredibly expensive to build and maintain. Your comment is very on point. If they slowly even out the atmosphere, they loose the speed. So they'll need to coordinate the door opening at exactly the right moment. And if it doesn't the whole instillation goes boom. I feel like it would be better just to use the money to buy more rocket fuel at t…

No they're definitely going to fail. The founders don't seem to understand how difficult this is. If you're going to build an accelerator you want it to accelerate over a very long distance and have it exit the vacuum well into the stratosphere if you can.

Pack it up, boys. Mlindner on hacker news says said you’re going to fail.

Re: SpinLaunch is building a centrifuge to launch satellites into orbit

#102

Post by viraptor »

noitpmeder wrote: post #96
mhandley wrote: post #93

I couldn't help wondering what happens to the counterweight. 100kg travelling at 5000mph works out as about 500MJ. For comparison, 1 tonne of TNT is about 4.2GJ, so the energy of the counterweight is about the same as 120kg of TNT. Looks like stopping the counterweight will produce a pretty big explosion, but probably not their biggest problem.

From the article " a counterbalance spinning opposite the rocket gets released at the same time, preventing the tether from becoming unbalanced and vibrating into oblivion "

Yes, but where is it released? Because if it's at the same time and the rocket goes up, the counterbalance goes down. And that means a big explosion right under your infrastructure.

Re: SpinLaunch is building a centrifuge to launch satellites into orbit

#103

Post by DennisP »

howlgarnish wrote: post #54
DennisP wrote: post #4

I hope it works because it'd be rad, but at $500K per 200-lb payload, they'll cost $2500/lb. That's only half as much as SpaceX Rideshare for the same size payload, today. If Starship works out, then SpaceX costs will drop enormously. Fuel is a minor portion of launch cost. SpinLaunch is saving fuel but throwing away rockets; it's going to be hard to compete with someone who throws away more fuel but saves the rocket…

They're claiming $500k per day and 5 launches per day, so the cost would be $500/lb. Obviously there's still an awful lot of work to be done to actually pull off that figure. If they do pull it off, the logical next step would be to use SpaceX-style reusable rockets as well, in which case you'd save both fuel and rocket costs.

The SyFy article said "up to five launches a day at the cost of around $500,000 per paying customer," which is a bit ambiguous, but it linked to Wired which says "A ride to space with SpinLaunch will cost under $500,000 per launch."

Making the rocket reusable would be the next step, but that's a nontrivial task itself, since it's effectively the upper stage which is the hardest part of reusability. Maybe it's easier for such a small rocket, I don't know. But even then they're just shaving a little fuel off a very low launch cost, in exchange for a 200 lb max payload that has to be hardened to 10,000 gees. The launch cadence would be an advantage today but Starship is supposed to launch three times per day, if the customers are there for it.

Re: SpinLaunch is building a centrifuge to launch satellites into orbit

#105

Post by clnhlzmn »

marsokod wrote: post #100
mlindner wrote: post #76

Earlier quoted context omitted.

They apparently tested spinning everyday objects up to 10,000g, which is great, but I wonder if they thought about bending moments induced when the thing is suddenly released.

And the mechanical and thermal shocks it gets when it passes from the vacuum chamber to the atmosphere. IMHO the centrifuge part is the easiest of their challenges.

That's what seems to me to be the biggest challenge too. Going from vacuum to 1 atm at 4000 mph has got to be quite a shock. Might as well just smash the thing into a wall.

Re: SpinLaunch is building a centrifuge to launch satellites into orbit

#106

Post by unnouinceput »

CGamesPlay wrote: post #17
beervirus wrote: post #3

“The reason it's hard to get to orbit isn't that space is high up. It's hard to get to orbit because you have to go so fast .” https://what-if.xkcd.com/58/ Sounds like this solves the easy part (getting to high altitude), but makes the hard part (getting to orbital velocity) even harder.

I think you're imagining that the rocket is fired directly vertically and peaks at some altitude, when the rocket ignite to "make it go fast". Instead, imagine the flings the rocket at a 45 degree angle so when it peaks in altitude it's already going quite fast. As other commentators in this thread point out, it's really an alternative for the primary stage rocket booster part, which doesn't just shoot a rocket strai…

The image on the site says 35 degree angle.

Re: SpinLaunch is building a centrifuge to launch satellites into orbit

#107

Post by greypowerOz »

sneak wrote: post #8
spicybright wrote: post #5

Earlier quoted context omitted.

Oh wow, I was wondering why bother building housing around it. That seems incredibly expensive to build and maintain. Your comment is very on point. If they slowly even out the atmosphere, they loose the speed. So they'll need to coordinate the door opening at exactly the right moment. And if it doesn't the whole instillation goes boom. I feel like it would be better just to use the money to buy more rocket fuel at t…

> And if it doesn't the whole instillation goes boom. The projectile is going to go boom when it hits the thick lower atmosphere going many times the speed of sound when it exits the vacuum chamber regardless.

I hear you :) but IIRC the US "rail guns" are generating muzzle velocities in this speed range (?)

I've seen very spectacular footage of these rounds tearing a hole in the atmosphere ... so maybe our shared intuition isn't reliable...

or maybe once you get a cross section bigger than a playing card, things become.... interesting at these speeds at sea level;)

Re: SpinLaunch is building a centrifuge to launch satellites into orbit

#108

Post by clnhlzmn »

supernova87a wrote: post #21

How does it deal with the sudden inrush of air and the object at supersonic speeds when the hatch is opened? Although, I guess for something about to go 5000 mph through the atmosphere, a little extra air probably isn't a big deal. Maybe the hatch cares though.

> 5000 mph > a little extra air

I think this is actually a big deal.

Re: SpinLaunch is building a centrifuge to launch satellites into orbit

#110

Post by moonbug »

ogre_codes wrote: post #37
JumpCrisscross wrote: post #33

Earlier quoted context omitted.

> wonder if that is going to put a crimp on their potential client list Solid state electronics and fuel. With respect to the former, nothing that requires stable orientation. I don't know of a propulsion system that can survive those forces.

That thing where they compress your ashes down and launch them into orbit... that may be their specialty.

So the customers who have no way to verify their payload made orbit.
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